mndrix

package prolog

/*
%% append(list,list,list)
%% append(+,+,+) is semidet.
%% append(+,+,-) is det.
%% append(+,-,+) is semidet.
%% append(+,-,-) is det.
%% append(-,+,+) is multi.
%% append(-,+,-) is multi.

mndrix

:- module(currency, [ atom_currency/2
                    , codes_currency/2
                    , currency//1
                    ]).

:- use_module(library(clpfd)).
:- use_module(library(dcg/basics), [integer//1]).
:- use_module(library(delay)).
:- use_module(library(error)).

mndrix

package main

import (
	"encoding/base32"
	"fmt"
	"strings"
)

func main() {
	data := "2246b2egzcc3ktvvoklo5cvzh4"

mndrix

:- use_module(library(clpfd)).

dcg(Arabic) -->
    { Arabic in 1..3999 },
    roman(Arabic),
    !.

roman(Total) -->
    { Rest #>= 0 },
    { Total #= Value + Rest },

mndrix

% Requirements, using Prolog syntax, to qualify for the foreign earned income exclusion
% See http://www.irs.gov/Individuals/International-Taxpayers/Foreign-Earned-Income-Exclusion

% facts which act as parameters to the loophole solver
:- dynamic
    us_citizen/0,
    us_resident_alien/0.

% See http://www.irs.gov/Individuals/International-Taxpayers/Foreign-Earned-Income-Exclusion-Can-I-Claim-the-Exclusion-or-Deduction
qualify :-

mndrix

% at_least//2 is like at_least//3 but ignores the specific matches found.
:- meta_predicate at_least(+,3,*,*).
at_least(N,Goal) -->
    at_least(N,Goal,_).


% at_least(N,Goal,Matches) consumes at least N matches of Goal.
% after that, it consumes as much as possible.
:- meta_predicate at_least(+,3,?,*,*).
at_least(N0,Goal,[X|Xs]) -->

mndrix

package main

import (
	"crypto/tls"
	"fmt"
	"net/http"
	"time"
)

// Make a GET request for a large (24 MB) file.  We only care about a single header field ("ETag")

mndrix

% Simplification and binarization of Prolog clauses.
%
% This code was my note paper while reading
% "The BinProlog Experience: Architecture and
% Implementation Choices for Continuation Passing
% Prolog and First-Class Logic Engines" by Paul Tarau.
%
% I find it especially pleasing that binary logic programs
% require only about half as many WAM instructions as
% traditional Prolog.  This should make it easy to build

mndrix

Tips for writing macros in SWI Prolog. This should eventually be expanded into a full blog post:

Only expand macros when requested

For each module that defines a macro, define a predicate like:

wants_my_fancy_macro :-
    prolog_load_context(module, Module),
 Module \== my_module, % don't expand macros in our own code

mndrix

:- module(bench, [call_ns/1,call_ns/2,compare/1]).

:- use_module(library(sweet)).

compare(Goals) :-
    maplist(run_comparison,Goals,Timings),
    keysort(Timings,Sorted),
    format("name\tns/op~n",[]),
    maplist(show_timing,Sorted).